CVE-2026-73866
Unauthenticated HTTP flaw in Oracle Helidon 4.5.0 allows full data compromise.
Is CVE-2026-73866 being exploited?
Not confirmed. CVE-2026-73866 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.40% probability of exploitation in the next 30 days.
How severe is CVE-2026-73866?
CVE-2026-73866 is rated Critical with a CVSS score of 9.1. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-73866?
Yes. A fix has been recorded for CVE-2026-73866. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-73866 affect?
CVE-2026-73866 affects Oracle Helidon 4.5.0 (Imperative Web Server). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-73866?
Restrict HTTP access, deploy WAF rules, and apply vendor patch/update when released.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Unauthenticated network attacker can create, delete, or modify all Helidon-accessible data (confidentiality & integrity compromise).
Immediate action required
- affected>= 4.0.0 and <= 4.4.1
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.